September gardening checklist

September is a busy month in the garden calendar. The days are getting longer and the weather warmer. The promise of a long hot summer and a bumper harvest is in the air!

Key gardening tips for September:

• It's spring and time to prepare your garden for planting
• Sow vegetable seeds for summer salads
• ‘Fresh is best’ plant vegetable seedlings
• Prepare and plant your herb garden
• Time to refresh and replenish your pots
• Continue to plant seed potatoes
• Plant and feed strawberries
• Plan your garden colour, plant seeds, seedlings and perennials for summer colour
• Continue to plant trees, shrubs and hedges
• Planning a new lawn? It’s time to sow seed

What to plant in Spring

September is prime time for gardeners, the soil’s warming, days are longer, and plants are ready to take off. There’s plenty to plant, harvest, and prep this month, so don’t wait. If your soil hasn’t been prepared yet, now’s the perfect time to start.

If the ground doesn’t need a full dig over, simply spread a few bags of compost across the bare soil and work it into the top layer with a fork. That’ll give your new plants the nutrients they need to thrive.

What vegetables to plant in September

September brings the end of winter crops and the start of spring planting in earnest. Harvest the last of your cold-season vegetables, including cabbage, kale, cauliflower, brussels sprouts, broccoli, bok choi, beetroot, parsnip, onions, peas, rocket, lettuce, and radish. Asparagus is also at its peak now; cut spears when they reach about 15cm tall.

It’s also the best time to start sowing and planting for a bumper summer harvest. Sow seeds now and transplant as the weather warms, once seedlings show at least two sets of true leaves.

Remember to stagger salad greens for a steady supply and to continue planting herbs, but hold off on basil and coriander in cooler areas until October.

Vegetables to Sow in September:

Sow directly into prepared beds or start indoors and transplant once seedlings show at least two sets of true leaves. In warmer areas, you can get a head start on heat-loving crops.

• Carrots
• Parsnip
• Beetroot
• Silverbeet
• Peas
• Lettuces
• Leeks
• Cabbage
• Tomato
• Capsicum
• Courgette
• Cucumber

Plant Vegetable Seedlings in September for:

• Lettuce
• Leeks
• Cabbage
• Corn
• Pumpkin
• Celery
• Onions
• Silverbeet
• Courgettes
• Eggplant (warm regions)
• Capsicum (warm regions)
• Cucumber (warm regions)

What vegetables are in season in Spring

In New Zealand, vegetables in season during spring include:

• Asparagus
• Artichokes
• Beans
• Beetroot
• Brussels sprout
• Eggplant
• Green peas
• Leek
• Parsnip
• Rhubarb
• Snow peas
• Watercress
• Yams

What fruit to plant in September

The last of winter citrus will be ready to harvest during September including limes, lemons, oranges and mandarins.

New fruit plantings go in best in September while the soil is warming and still holding moisture.

• Passionfruit: Plant early in warm regions. They need free-draining soil, a sturdy support structure, and frost protection for young foliage. See our Easy As guide for detailed tips.
• New citrus trees: Pinch off flowers from young trees to help them put energy into growing strong first. This will benefit the tree by letting it concentrate on growing before producing. We’ve got more information on this in our how to grow citrus trees guide.
• Potted deciduous fruit trees and vines: These transplant well in September, get them into the ground now.

Fruit trees and vines ready to plant in September include:

• Apple
• Pear
• Raspberry
• Strawberry
• Blueberry
• Blackberry
• Boysenberry
• Feijoa
• Lemon
• Orange
• Mandarin
• Lime

Fruits in season in Spring

In Spring, the following fruits are in season in New Zealand:

• Grapefruit
• Golden Kiwifruit
• Green Kiwifruit
• Lemon
• Oranges
• Strawberries

What flowers bloom in Spring?

Spring is when gardens across New Zealand come alive with colour. Many classic favourites burst into bloom as the weather warms and daylight stretches. This includes:

• Daffodils
• Tulips
• Freesias
• Hyacinths
• Iris (Dutch and bearded)
• Ranunculus
• Anemones
• Bluebells
• Blossoms (cherry, plum, peach)

What flowers to plant in Spring

September is the perfect time to refresh your garden beds, pots and containers with vibrant spring colour. Keep replacing spent winter flowers with fresh spring annuals, adding a pinch of blood and bone at planting to give them a strong start. When replanting pots, remove any tired, depleted soil and replace it with fresh container mix before adding your flowers.

Sow seeds now and transplant seedlings as the weather warms and plants develop at least two sets of true leaves.

Flowers to sow now:

• Begonias
• Carnations
• Cosmos
• Flowering kale
• Impatiens
• Lobelia
• Salvia
• Viola
• Poppies

Seedlings to plant now:

• Ageratum
• Alyssum
• Aster
• Begonia
• Californian poppy
• Carnation
• Cosmos
• Dahlia
• Impatiens
• Marigold
• Petunia

Trees and shrubs tips during September

• Plant new trees and shrubs dig compost with the soil and add a long term fertiliser to the bottom of the hole.
• Plant that hedge, use a long term fertiliser at the bottom of each hole. For easy watering use a soaker hose, lay out along the planting line, move when necessary.
• Plant large shade trees, stake firmly at the time of planting.
• Choose new camellias and rhododendrons, they like an acidic soil and semi shady position.

Lawn tips for September gardening

• For more on growing and caring for lawns see our lawn guide.
• Sow new lawn; take advantage of the spring rain and warmth to germinate new seed.
• Fertilise your lawn for spring. Apply evenly across the whole lawn and water in.
• Spray for onehunga weed, it comes in to flower in September and October now is the time to spray for it.
• Attack the broadleaf weeds in the lawn. Wait for a calm day before using any sprays.